问题
多项选择题
An American professor has prepared a letter of recommendation for his student, and his student is expected to say "()".
A. Thank you very much
B. I feel so sorry that it has taken you so much time
C. I feel so sorry that it has caused you so much trouble
D. I really appreciate your help
答案
参考答案：A, D
解析：
主要考查英文里的致谢用语。
英语中最常用的致谢用语有Thank you very much, I really appreciate your help等。